In looking up some locations in Google Maps today, I found that the map images were not displaying. The searches worked, and I did get the list of possible matches on the left side. Thanks to some searching through Google I found the problem. The current Skype add-on (v.18.104.22.168) for Firefox is causing this problem. I'm not sure how they are related, but by disabling the Skype add-on fixed the problem.
It appears this Skype Add-on is also causing screen redraw issues for some users of Firefox as well.